LTC3801B Datasheet | Linear Technology

LTC3801/LTC3801B Micropower Constant Frequency Step-Down DC/DC Controllers in Thin SOT Features s High Efficiency: Up to 94% s Very Low No-Load Quiescent Current: Only 16µA (LTC3801) s High Output Currents Easily Achieved s Internal Soft-Start s Wide VIN Range: 2.4V to 9.8V s Low Dropout: 100% Duty Cycle s Constant Frequency 550k Hz Operation s Burst Mode® Operation for High Efficiency at Light Loads (LTC3801) s Burst Mode Operation Disabled for Lower Output Ripple at Light Loads (LTC3801B) s Output Voltage as Low as 0.8V s ±1.5% Voltage Reference Accuracy s Current Mode Operation for Excellent Line and Load Transient Response s Only 6µA Supply Current in Shutdown (LTC3801) s Low Profile (1mm) SOT-23 Package U APPLICATIO S s 1- or 2-Cell Li-Ion Battery-Powered Applications s Wireless Devices s Portable puters s Distributed Power Systems DESCRIPTIO The LTC®3801/LTC3801B are constant frequency current mode step-down DC/DC controllers in a low profile (1mm max) 6-lead SOT-23 (Thin SOTTM) package. The parts provide excellent AC and DC load and line regulation with ±1.5% output voltage accuracy. The LTC3801 consumes only 195µA of quiescent current in normal operation, dropping to 16µA under no-load conditions. The LTC3801/LTC3801B incorporate an undervoltage lockout feature that shuts down the device when the input voltage falls below 2.2V. The LTC3801 automatically switches into Burst Mode operation at light loads which enhances efficiency at low output current. In the LTC3801B, Burst Mode operation is disabled for lower output ripple at light loads. To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550k Hz allows the use of a small inductor. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. Thin SOT is a trademark of Linear Technology Corporation. TYPICAL...